It is known to use retrograde displays, which use substantially triangular sectors of the dial. However, the retrograde display is disconcerting for some users, who prefer a continuous display.
In FR Patent No. 647 409 in the name of Lancel, the time display is made to pass over a circular graduated sector via one of three cross-shaped wheel sets, pivoted by a Y-shaped support that always pivots in the same direction, all of which are concealed by a disc, with the exception of a single branch of a cross, shown in an annular space opposite the graduated circular sector.
Likewise, EP Patent No. 0 950 932 in the name of Daniel Roth and Gerald Genta discloses a wheel set that pivots continuously and carries two dual, opposite, pivoting hands, which are concealed except for an annular sector, opposite a graduated circular sector over an amplitude of 180°.
Continuous mechanisms with several arms are also known, which may be combined with an identical mechanism rotating in the opposite direction facing the same dial, as in CH Patent No. 699 117, in the name of Agenhor.
“Paul Picot Technograf” watches are also known, including two half-dials in a half-moon on either side of a central dial, each of which has a different function and includes an internal scale and an external scale, opposite which a respectively short or long end of the same dual hand is positioned.
The general principle of these known mechanisms is to combine a mask and one or more special hands so as to give the appearance of discontinuity.
FR Patent No. 2 793 898, in the name of TIMENTEL PTY discloses a watch with two juxtaposed cases, wherein the two movements are synchronised by electric conductors, each of the movements being provided with a retrograde display, such that the hands thereof, each operated by a motor, are either both stopped behind a mask, or moving on a respectively lower or upper half-dial.
In short, although mechanisms exist with particular arrangements of hands, or more generally display fingers, opposite a single graduated dial or concentric graduated dials, they have a retrograde display, the operation thereof is sometimes complex and their dimensions are ill-suited to the aforementioned constraints on use of the available space.